In June 2013, Commonwealth Dairy completed a $12-million expansion of its $28.5-million plant to support a new product line. And on Monday, Thomas Moffitt, Commonwealth Dairy's president, returned from Casa Grande, Ariz., where it and its partner, Ehrmann AG, just opened a new facility. The state-of-the art yogurt manufacturing facility in Arizona was built by the same company that built Commonwealth's factory in Brattleboro, said Moffitt, but it's twice the size.